This invention relates to a dot matrix type printer and, more particularly to improvement of its carriage mechanism including a printer head which comprises a plurality of printer elements aligned in the direction across a sheet of paper set on the platen of the printer to be printed.
The printer of this class is able to perform high speed operation to print various kinds of characters, so that it has become more popular to use the printer as an output means for systems such as a computer or the like.
As is known well, the printing speed of such a printer is basically determined by two factors. One is a period required for one reciprocation of the printer head and the other is a period required for repetitive printing motion of printer elements which are aligned in parallel with each other on the printer head. For realizing high speed operation, therefore, it is needed to shorten such two kinds of periods. It should be noted, however, that the printer head contains a lot of parts for constituting itself, thus resulting in a considerably large inertia when moving. Accordingly, the more speedily the printer is operated, the more often undesirable vibration is caused and the larger noise becomes also. The problem of high speed operation of the printer might be improved to some extent when generation of vibration and noise during the operation is satisfactorily suppressed by some means. If such is done well, however, there should still be problems, for instance the problem of protecting wear of parts which are working in slidable and rotating mechanism, the problem of maintaining such parts and others in good condition and so forth. High speed operation naturally causes high speed wear of parts, thus demanding more frequent maintenance work of inspecting and lubricating the mechanism and of repairing or replacing parts worn. To realize high speed operation by relying on the prior art carriage mechanism, it is needed to use a lot of sliding and rotating parts. This causes difficulties not only in miniaturizing the carriage mechanism but also in doing fine adjustment of the mechanism as well as maintanence of the same.